Re: SV: Cult: Leaf spots

Gunnar asks
>there are some thing that im also wondering over and that is leaf spots.
>I had very very much last summer, suprising....yes,     on flavescens not a
>single spot.
>how can i avoid that??

Hi, Gunnar! In my garden certain cultivars are far more susceptible <sp?>
to leaf spot than others. Last summer, we had terrible leaf spot all over
the county, because it was such a humid year and the aphids and other
carriers were out in force. This winter, even though we've received far
more ran than normal and the temps have been mild, I only have two
cultivars that are much troubled by spot: LEMON PUNCH and BEVERLY SILLS.

This tells me the control methods we used last summer work well. Begin by
leaving breathing room between plants when you make your garden. Don't
crowd the irises together. That won't completely prevent infection but it
will limit its spread.

Then keep your beds clean. Remove dead foliage often. When you see spots,
cut off the leaf below them and burn or otherwise remove the cuttings from
your garden completely - only compost if you have a really hot compost
pile. the county agent here suggests that you dip your scissors into a 10
percent bleach solution after each cut, and take care that you don't handle
healthy foliage with the hand that collects the sickened leaves.

Visit the garden daily and remove aphids, leaf hoppers and cucumber beetles
(these are our common pests. No doubt you have others.).

Leaf spot lives two seasons. If you have it this year, it will be back next
year, but if you control it this year, it won't come back as strong. Very
large gardens treat mass infections with rotating fungicide sprays, and
they routinely cut back foliage in fall. If you have a smaller garden,
there's no reason to do this just to avoid leaf spot, because trimming
individual leaves when you see infection works very well.

Another general observation, based upon what we've seen in our display beds
(all beardeds), one of which has improved soil and the other having poor
soil: Plants in better soil seem less affected by leaf spot.


celia
storey@aristotle.net
Little Rock, Arkansas, USDA Zone 7b
-----------------------------------
257 feet above sea level,
average rainfall about 50 inches (more than 60" in '97)
average relative humidity (at 6 a.m.) 84%.
moderate winters, hot summers ... but lots of seesaw action in all seasons
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